UAN and Cognitive Walkthrough
Comments on Napier Solutions

Phil Gray
25March 1998

General Comments on UAN

  1. UAN has four basic columns, viz., user actions, feedback, system state and application operations (sometimes called "connection to computation"). References to application operations (like actually changing the width of the table column) should appear in the application operations column, not in the system state column.
  2. The column labelled "System State" (or "UI State") is intended to include state, not otherwise captured in the user actions themselves, which can affect the consequences of user actions. Sometimes these states are referred to as "modes". In this example, the only significant states are the selected column, which affects the contents of the subsequent dialogue box, and (perhaps) the activation of the dialogue box itself. Selecting a menu by mousing down on its label creates a state which is indicated by the description of the user action as selecting the menu item by name; including this in System State isn't wrong, but is unnecessary.
  3. While you don't have use the special UAN symbols for the user action and feedback columns, it might have been useful to attempt them. This is an exercise in using UAN, after all!

General Comments on Cognitive Walkthrough

  1. The purpose of a cognitive walkthrough is to identify potential usability problems. The input to the walkthrough is a scenario, which will usually be incomplete, especially with respect to information about what the user already knows. Often, one won't know for sure, but can hypothesize a possible problem. For example, we know that Kim has used Macs and Word before, but we don't know if she has ever created or formatted a table. Therefore, it is possible that she doesn't know how to select a column nor the relevant menu item for column resizing. Some of you caught this potential problem, but several groups did not.
  2. One of the most likely problems to be encountered is the fact that Kim must be very lucky to pick the right value on her first attempt. There is nothing in the interface to indicate the correct value and no way of determining it other than by trial and error.
  3. Giving a likely level of seriousness for each problem can help in using the cogntive walkthrough results, e.g., in prioritising the problems for further investigation.